Systems and methods for spinal surgery

ABSTRACT

Disclosed herein are methods and devices for distracting adjacent vertebrae during surgical procedures for implanting spinal prostheses. In an exemplary embodiment, a distractor is disclosed that maintains the empty space between adjacent vertebrae following a discectomy, and that can removably mate with other surgical instruments, such as, for example, a filler bar, an implanting tool, or a funnel. In other embodiments of the present invention a distractor is disclosed having various features to assist in implanting a spinal prosthesis, such as, for example, an angled distal end and/or an expandable paddle. In another embodiment of the present invention, an articulating inserter is disclosed. Moreover, various implants and funnels are also disclosed herein.

RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.10/579,146, filed Feb. 22, 2007, which is a U.S. national phaseapplication filed pursuant to 35 U.S.C. 371 from PCT/US05/004136, filedFeb. 9, 2005, which claims the benefit of the filing date of U.S.Provisional Patent Application Ser. No. 60/543,030, filed Feb. 9, 2004,all of which are herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to surgical instruments, and in particularto methods and devices for implanting spinal prostheses.

BACKGROUND

Spinal fusion surgeries, that is, the use of bone graft material topromote specific vertebrae to grow together into a solid and stableconstruct, are a common method of treating patients with severe backpain. For fusion to occur within the disc space, the surgeon must firstremove the damaged disk material. Once the disk material is removed, theempty space left between the upper and lower vertebrae is distracted torelieve pressure from neural elements and to provide space for entry ofsurgical tools and/or implants. A bone graft, or interbody cage withbone, is then inserted into the empty disc space to promote bone growthfrom vertebral body to vertebral body. Recently, minimally invasivetechniques have improved fusion procedures by causing less damage totissue surrounding the damaged disk and allowing for faster recovery bythe patient.

One drawback associated with current instruments used to perform spinalfusion surgery, especially minimally invasive surgery, is that theytypically provide inadequate protection for sensitive nerve tissuesurrounding the surgical site. The smaller access portals used inminimally invasive surgery allow sensitive tissue to be located veryclose to the surgical site. Further, using current instruments withinthese tight confines often impedes the surgeon's visibility, making theultimate placement of the implant difficult.

Accordingly, there remains a need for improved surgical instruments, andin particular for surgical instruments used for implanting spinalprostheses.

SUMMARY

Disclosed herein are various methods and devices for implanting spinalprostheses. In one aspect, a surgical instrument system includes adistractor having a shaft, a paddle located at the distal end of theshaft, and a filler bar shaped to removably engage the shaft and paddleof the distractor. In an exemplary embodiment, when the filler bar isengaged to the distractor, the filler bar provides rigidity and torquestrength so that the distractor can be inserted between adjacentvertebrae in a first orientation and rotated to distract adjacentvertebrae. A guide feature configured to mate with at least one of animplant or an implant inserter can extend along at least a portion ofthe shaft and the paddle, or alternatively, the paddle can furthercomprise at least one overhanging tab on at least one of the superiorand inferior surfaces. Moreover, in a further exemplary embodiment, thesurgical instrument system can comprise a minimally invasive access portthrough which is distractor is dimensioned to be placed.

In a further embodiment, at least one of the superior and inferiorsurfaces of the paddle can include a means for preventing migration ofthe distractor during distraction, such as, for example a bone engagingelement or at least one expansion shoulder. The distractor paddle canalso include an angled guide feature that is configured to guide animplant through a partial rotation to a desired angle. The angled guidefeature can have a variety of configurations, such as an angled surfaceintegral with a distal portion of the paddle, or, a movable shim thatcan be either retractable or a memory metal shim. The implant insertercan also include an angled distal end or an articulating implant holderoperable to rotate an implant to a desired angle.

In a further aspect, a surgical instrument system includes a distractorhaving a shaft and a paddle located on the distal end of the shaft. Thedistractor paddle and the shaft can also present a guide surface forguiding the placement of an implant when the distractor is in thedistraction orientation. The distractor paddle can also include anangled guide feature that is configured to guide an implant through apartial rotation to a desired angle. The angled guide features can havea variety of configurations, such as an angled surface integral with adistal portion of the paddle, or, a movable shim that can be eitherretractable or a memory metal shim. The distractor paddle can alsoinclude a first height dimension when presented in an insertionorientation and a second height dimension when rotated approximately 90degrees to a distraction orientation, the second height dimension beinggreater than the first height dimension, the paddle having inferior andsuperior surfaces for contacting adjacent vertebrae in the distractionorientation. In a further embodiment, at least one of the superior andinferior surfaces of the paddle can include a means for preventingmigration of the distractor during distraction, such as, for example abone engaging element including at least one tooth or at least oneexpansion shoulder operable to extend beyond at least one of theinferior or superior surfaces so as to increase the second heightdimension.

In a further embodiment, the surgical instrument system can also includean implant inserter having an angled distal end, the angle correspondingapproximately to the angle provided on the angled guide feature orhaving an articulating implant holder operable to rotate an implant to adesired angle. Moreover, the surgical instrument system can also includeguide features extending along the shaft and paddle configured formating with at least one of an implant and an implant inserter to guidethe insertion of an implant along the distractor. In a furtherembodiment, the surgical instrument system can include a filler barshaped to removably engage the shaft and paddle of the distractor,wherein when the filler bar is engaged to the distractor, the filler barprovides rigidity and torque strength so that the distractor can beinserted between adjacent vertebrae in a first orientation and rotatedto distract the adjacent vertebrae. The surgical instrument system canalso include a minimally invasive access port through which thedistractor is dimensioned to be placed.

In another aspect, a surgical instrument system includes a distractorhaving a shaft and a paddle located on the distal end of the shaft, thepaddle further including inferior and superior surfaces configured forcontacting adjacent vertebrae to define a distraction height. Thesurgical instrument system also includes at least one expansion shoulderoperable to extend beyond at least one of the inferior or superiorsurfaces of the paddle so as to increase the distraction height. In oneembodiment, the surgical instrument system can include a shim that canbe slidable along a longitudinal axis of the distractor, and that canfurther include at least one expansion shoulder such that the distalmovement of the shim causes the at least one expansion shoulder toincrease the distraction height. The shim can also include an angleddistal end such that distal movement of the shim causes the angleddistal end to extend at an angle from a distal end of the paddle to forman angled guide. The system can further include a linkage assemblyslidably connecting the paddle and the at least one extension shoulder,or, alternatively, a slidable shim having a shoulder for contacting thelinkage assembly to effect changes in the distraction height. Moreover,the distractor paddle and the shaft can present a guide surface, whichcan optionally include a guide feature, for guiding the placement of animplant when the distractor in the distraction orientation.

In still another aspect, the surgical instrument system can include anarticulating implant inserter including a shaft, and an articulatableimplant holding element located at the distal end of the shaft. Thearticulatable implant holding element can be operable from the proximalportion of the shaft to releasably hold an implant. Moreover, thesurgical system can further include an implant having a connectingelement that cooperates with the articulatable implant holding elementto allow articulation of the implant to a desired angle. The implantconnecting element can engage either an internal or external portion ofthe implant. Further, the articulatable implant holding element caninclude two sliding elements having distal implant impaction faces, suchthat the relative sliding of the sliding elements in a proximal-distaldirection along the shaft selectively articulates the implant to adesired angle. The position of the handle can also act as a visualindicator for an angle through which the implant has been rotated.

In still another aspect, a surgical instrument system disclosed hereinincludes a means for distracting adjacent vertebrae, an implant, a meansfor inserting the implant into a space between the adjacent vertebraeupon insertion, and a means for rotating the implant to a desired anglebetween the adjacent vertebrae upon insertion. In certain embodiments,the means for distracting adjacent vertebrae includes two distractionpaddles movable away from each other to distract adjacent vertebrae, ora distractor paddle having a first height dimension when presented in aninsertion orientation and a second height dimension when rotatedapproximately 90 degrees to a distraction orientation, the second heightdimension being greater than the first height dimension.

Moreover, the surgical instrument system can also include a shaft, apaddle located on the distal end of the shaft having inferior andsuperior surfaces configured for contacting adjacent vertebrae to definea distraction height, and at least one expansion shoulder operable toextend beyond at least one of the inferior or superior surfaces so as toincrease the distraction height. While the means for insertion can vary,it can include a ratchet gun, or an articulating implant inserteroperable to place the implant at a desired angle. The means for rotatingthe inserter can also vary can, and can include an articulating implantinserter or angled guide features located on a distal end of the meansfor distracting. Moreover, the implant can have a variety ofconfigurations such as domed inferior and superior surfaces configuredto correspond to surfaces of adjacent vertebra, or alternatively, aleading end having a bullet-shaped cross-sectional profile in at leasttwo planes.

A method is provided in another aspect. In particular, a minimallyinvasive surgical method includes inserting a distractor assemblythrough a minimally invasive surgical access port and between adjacentvertebrae in an insertion orientation, the distractor assembly includinga shaft, and a paddle located on the distal end of the shaft and afiller bar removably engaged to the shaft and the paddle of thedistractor. The method can further include rotating the distractorassembly to a distraction orientation to distract the adjacentvertebrae, disengaging the filler bar from the shaft and paddle, andremoving the filler bar through the minimally invasive access port whileleaving the shaft and paddle in place to maintain a desired distractionof the adjacent vertebrae. In one embodiment, the distractor paddleincludes a first height dimension when presented in an insertionorientation and a second height dimension when rotated approximately 90degrees to a distraction orientation, the second height dimension beinggreater than the first height dimension. The paddle further includesinferior and superior surfaces for contacting adjacent vertebrae in thedistraction orientation.

Moreover, the method can also include inserting an implant between theadjacent vertebrae using the shaft and paddle as a guide for placementof the implant. Alternatively, the method can include using a paddlewith an angled guide element on its distal end, inserting the implantusing the shaft and paddle as a guide for placement, and rotating theimplant to a desired angle based on the angled guide element.

In a further aspect, an implant is provided. In one embodiment, theimplant has a blended or “bullet-shaped” cross-sectional profile in atleast two planes. In a further embodiment, the implant has a domedsuperior and/or inferior configured to conform generally to one or bothadjacent vertebral end-plates at a predetermined angle of orientation ofthe implant. The implant can be combined with either a distractor thatcan guide the implant to the desired orientation (including a partialrotation of the implant) or an articulating insertion tool that canrotate the implant to the desired position.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a side perspective view of one embodiment of a distractorassembly;

FIG. 2 is a side perspective view of one embodiment of the distractor ofthe distractor assembly of FIG. 1;

FIG. 3 is a side perspective view of the distractor assembly of FIG. 1upon insertion into an intervertebral space;

FIG. 4 is a top perspective view of the distractor assembly of FIG. 1upon insertion into an intervertebral space;

FIG. 5 is side perspective view of the distractor assembly of FIG. 1upon insertion into an intervertebral space;

FIG. 6 is another side perspective view of the distractor assembly ofFIG. 1 upon insertion into an intervertebral space;

FIG. 7 is a side perspective view of an implant being inserted into anintervertebral space using the distractor assembly of FIG. 1;

FIG. 8 is another side perspective view of an implant being insertedinto an intervertebral space using the distractor assembly of FIG. 1;

FIG. 9 is a side perspective view of another embodiment of a distractor;

FIG. 10 is a side perspective view of an implant being inserted into anintervertebral space using the distractor of FIG. 9;

FIG. 11 in another side perspective view of an implant being insertedinto an intervertebral space using the distractor of FIG. 9;

FIG. 12 is a side perspective view of another embodiment of a distractorbeing inserted into an intervertebral space;

FIG. 13 is a side perspective view of an implant being inserted into anintervertebral space using the distractor of FIG. 12;

FIG. 14 is a side perspective view of another embodiment of adistractor;

FIG. 15 is a side perspective view of the distractor of FIG. 14 uponinsertion into an intervertebral space;

FIG. 16 is another side perspective view of the distractor of FIG. 14upon insertion into an intervertebral space;

FIG. 17 is a side perspective view of an implant being inserted into anintervertebral space using the distractor assembly of FIG. 14;

FIG. 18 is a side perspective view of another embodiment of a distractorupon insertion in an intervertebral space;

FIG. 19 is a side perspective view of the distractor of FIG. 18;

FIG. 20 is another side perspective view of the distractor of FIG. 18upon insertion into an intervertebral space;

FIG. 21 is a side perspective view of another embodiment of adistractor;

FIG. 22 is a side perspective view of the distractor of FIG. 21 uponinsertion into an intervertebral space;

FIG. 23 is another side perspective view of the distractor of FIG. 21;

FIG. 24 is a side perspective view of another embodiment of a distractorupon insertion into an intervertebral space;

FIG. 25 is another side perspective view of the distractor of FIG. 24upon insertion into an intervertebral space;

FIG. 26 is another side perspective view of the distractor of FIG. 24upon insertion into an intervertebral space;

FIG. 27 is a side perspective view of an implant being inserted into anintervertebral space using one embodiment of an inserter;

FIG. 28 is another side perspective view of an implant being insertedinto an intervertebral space using the inserter of FIG. 27;

FIG. 29 is a side perspective view of the inserter of FIG. 27;

FIG. 30 is a side perspective view of another embodiment of an inserter;

FIG. 31 is another side perspective view of the inserter of FIG. 30;

FIG. 32 is a magnified view of the distal end of the inserter of FIG.30;

FIG. 33 is another magnified view of the distal end of the inserter ofFIG. 30;

FIG. 34 is a side perspective view of an implant being inserted into anintervertebral space using another embodiment of an inserter;

FIG. 35 is another side perspective view of an implant being insertedinto an intervertebral space using the inserter of FIG. 34;

FIG. 36 is a side perspective view of another embodiment of an inserter;

FIG. 37 is a side perspective view of an implant being inserted into anintervertebral space using another embodiment of an inserter;

FIG. 38 is a side perspective view of another embodiment of a distractorassembly;

FIG. 39 is a side perspective view of the distractor assembly of FIG. 38upon insertion into an intervertebral space;

FIG. 40 is a side perspective view of another embodiment of a distractorassembly upon insertion into an intervertebral space;

FIG. 41 is another side perspective view of an implant being insertedinto an intervertebral space using the distractor assembly of FIG. 40;

FIG. 42 is a side perspective view of an implant being inserted into anintervertebral space using another embodiment of a distractor assembly;

FIG. 43 is another side perspective view of the distractor assembly ofFIG. 42 upon insertion into an intervertebral space;

FIG. 44 is a side perspective view of one embodiment of an implant;

FIG. 45 is a side perspective view of the implant of FIG. 44;

FIG. 46 is another side perspective view of the implant of FIG. 44; and

FIG. 47 is a side perspective view of one embodiment of a funnel.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Disclosed herein are methods and devices for distracting adjacentvertebrae and/or inserting spinal implants during surgical proceduresfor repairing a patient's spine. In an exemplary embodiment, adistractor is disclosed that maintains the empty space between adjacentvertebrae following a discectomy, and that can removably mate with othersurgical instruments, such as, for example, a filler bar, an implantingtool, or a funnel. In other embodiments of the present invention adistractor is disclosed having various features to assist in implantinga spinal prosthesis, such as, for example, an angled distal end and/oran expandable paddle. In another embodiment of the present invention, anarticulating inserter is disclosed. Moreover, various implants andfunnels are also disclosed herein. A person skilled in the art willappreciate that, while the methods and devices are described inconnection with certain spinal procedures, the methods and devicesdisclosed herein can be used for a variety of surgical procedures.

Certain features and aspects of the present invention will now bedescribed by reference to the distractor assembly and associatedelements illustrated in FIGS. 1 to 8, which illustrate a distractorassembly system and method for inserting a spinal prosthesis.

FIG. 1 illustrates one embodiment of a distractor assembly 10 disclosedherein having a distractor or guide arm 12, a guide filler bar 26, and amodular handle 16. While the distractor 12 can have a variety ofconfigurations that enable it to maintain the space between adjacentvertebrae following a discectomy, as shown in FIG. 2, the distractor 12has proximal and distal ends 12 a, 12 b with an elongate shaft 14extending therebetween. Attached to the proximal end 12 a of thedistractor 12 is a handle 16 (or a portion thereof) for gripping by thesurgeon. While the handle 16 can be either fixedly or removablyattached, in an exemplary embodiment, the handle 16 is removablyattached to the shaft 14 by any means known in the art, such as, forexample, a screw or a spring plunger, so that the surgeon can remove itto achieve increased visibility to the surgical site.

Extending distally from the handle 16 is an elongate shaft 14. While theshaft 14 can have a variety of sizes, it should have a diameter that,upon insertion into the intervertebral space, allows sufficient spacefor the insertion of other surgical tools, such as a filler bar or aninserter for example, as well as an implant. Additionally, the shaft 14can have a variety of shapes, such as circular, ovular, rectangular orsquare. As shown, the shaft 14 is rectangular and generally flat.

The shaft 14 can also have a variety of configurations that allow formating with another surgical instrument, such as, for example, a fillerbar, an inserter, a funnel, or any other instrument used in theimplanting of a spinal prosthesis. In an exemplary embodiment, the shaft14 can have a guide feature 18 such as a tooth or groove that can matewith a corresponding guide feature on another surgical instrument. Theguide feature 18 can be formed either throughout the entire length ofthe shaft 14 or on a partial length thereof. The guide feature 18 canalso have a variety of configurations depending upon the mating featuresof the corresponding surgical instrument. For example, in oneembodiment, the guide feature 18 can be protrude from the shaft 12, or,alternatively, the guide feature 18 can be recessed within the shaft 12.The guide feature 18 can also have a variety of shapes, however in anexemplary embodiment, the guide feature 18 has a C-shape with twoopposed sides that are either straight or curved. In addition, outerfeatures, including the cross-sectional shape of the shaft itself, canform mating or guiding features.

Attached to the distal-most end of the shaft 14 is a distracting paddle22 that, upon insertion into the cavity, can be rotated to distractadjacent vertebrae to maintain the integrity of the cavity between them.As shown, paddle 22 has proximal and distal ends 22 a, 22 b connected bysuperior and inferior sides 22 c, 22 d and having a front or guidingface 22 e and a back face 22 f. While paddle 22 can have a variety ofshapes, such as rectangular, circular or oblong, the illustrated paddle22 is generally rectangular with rounded corners. The paddle 22 can alsohave a variety of sizes to provide a desired level of distraction, solong as it has a width that is less than the diameter of any accessportal into the intervertebral space. In an exemplary embodiment, thepaddle 22 has a width that is less than about 19 mm, and more preferablyabout 7 mm. The paddle may also be shaped so as to provide an anglebetween the inferior and superior sides to match a desired angle ofdistraction.

The paddle 22 can have a variety of additional features to assist thesurgeon with distraction, which can be used alone or in combination withone another. In addition to those features discussed in more detailbelow, in one embodiment, the distal end 22 b of the paddle 22 can bearcuate to allow for easier insertion into the intervertebral space 42.In addition, the superior and/or inferior sides 22 c, 22 d can havevarious geometries to enhance the distraction of the intervertebralspace 42, such as laterally extending surfaces that provide a largersurface area to contact the vertebrae. The back side 22 f can also bedome-shaped to aid the surgeon in minimizing damage to the neural tissuesurrounding the intervertebral space 42. One of superior and inferiorsides 22 c, 22 d can also be provided with a bone engaging element suchas one or more teeth to prevent migration of the paddle duringdistraction.

Additionally the paddle 22 can have a variety of features to assist thesurgeon with positioning of the implant 48 within the intervertebralspace 42. In addition to those features discussed in more detail below,guide surface 22 e of the paddle 22 can include at least one guidefeature such as guide feature 18 extending from the shaft 14 to engage acorresponding element in an implant or implant inserter. Alternatively,the implant or implant inserter can be guided by a flat guide surface 22e or by external features of the shaft 14.

As noted above and referring back to FIG. 1, a filler bar 26 can beremovably mated to the distractor 12 to provide rigidity and torquestrength to the distractor 12 during insertion into the cavity 42 anddistraction of the adjacent vertebrae. As shown in FIG. 1, the fillerbar 26 has proximal and distal ends 26 a, 26 b with a shaft 28 extendingtherebetween. The proximal end 26 a can have a variety of configurationsto assist the surgeon with placement and removal of the filler bar 26from the distractor 12, however as shown the filler bar 26 has aT-shaped handle 30. Alternatively, the proximal end of the filler barcan include a portion of a handle that can mate with a correspondinghandle portion on a distractor, such that when mated together, acomplete handle is formed. While the handle portions can mate to oneanother in a variety of ways, in an exemplary embodiment, the handleportions are mated together by a spring lock mechanism.

Extending distally from the T-shaped handle 30 is an elongate shaft 28.While the shaft 28 can have a variety of sizes, as shown it has adiameter that is less than the diameter of the distractor. Additionally,the shaft 28 can have a guide feature 32 that corresponds to the guidefeature 18 on the distractor 12. That is, the guide feature 32 can beeither protruding or recessed, and have a variety of shapes, such asC-shaped with two opposed sides that can be either straight or curved.While the guide feature 32 can be formed throughout the entire length ofthe shaft 28 or on a partial length thereof, as shown, the groove 32 isformed throughout the entire length of the shaft 28.

Fixedly attached to the distal most end of the shaft 28 is a stabilizingplate 34. The plate 34 can have any size so long as it is able to fitwithin the intervertebral space alongside the distractor 12, however inan exemplary embodiment the plate 34 is shaped such that it can nestwithin the distracting paddle 22, and in particular, within thelaterally extending portions of superior and inferior surfaces 22 c, 22d. Thus, in an exemplary embodiment, the plate 34 has width that isslightly smaller than the distracting paddle 22 and complementary inshape thereto.

In a further embodiment, an implant inserter can be used with thedistractor to form a distraction and insertion system. Generally, theinserter can be similar to inserters known in the art, as well as theinserter 46 shown in FIGS. 7 and 8. As shown in FIGS. 7 and 8, theinserter 46 has proximal and distal ends 46 a, 46 b with a shaft 52extending therebetween. While the proximal end 46 a can have a varietyof configurations, in an exemplary embodiment it can have a handle (or aportion thereof) fixedly or removably attached thereto.

Extending distally from the handle of the inserter 46 is an elongateshaft. While the shaft 52 can have a variety of configurations, theshaft 52 can also optionally include a guide feature 50 that correspondsto the guide feature 18 on the distractor 12, such that the inserter 46can be mated to the distractor 12. Thus, depending upon theconfiguration of the guide feature 18 on the distractor 12 the guidefeature 50 on the inserter 46 can be either protruding or recessed, andcan be, for example, C-shaped with two opposed sides that are eitherstraight or curved. Moreover, the guide feature 50 on the inserter 46can be formed either throughout the entire length of the shaft 52 or ona partial length of the shaft 52. Alternatively, the inserter may simplybe guided by a flat surface on the shaft 14 and/or paddle 22 on thedistractor 12 or by an external feature of the shaft 14 such as, forexample, its superior and/or inferior surfaces. Removably mated to thedistal most end of the shaft 52 is an implant 48, various embodiments ofwhich will be discussed below.

In use, as shown in FIGS. 3 to 8, the distraction assembly 10 isinserted into the intervertebral space 42 (that is, the space betweensuperior and inferior vertebrae 41, 43) following the excision of diskmaterial. The distraction assembly 10 is then rotated approximately 90°such that the paddle 22 is substantially perpendicular to the superiorand inferior vertebrae 41, 43, so as to enlarge and/or maintain adesired space within the cavity 42 by the force applied to the vertebraeby superior and inferior surfaces 22 c, 22 d during rotation. Oneskilled in the art will appreciate that where the instruments are usedin a minimally invasive surgical procedure, such as shown in FIGS. 5 to8, access to the surgical site can be gained using an access port suchas cannula 51.

Following distraction of the cavity 42, the filler bar 26 can be removedfrom the distractor 12 to decrease the amount of space that the assembly10 requires in order to make room for further tools and/or implants aswell as to improve the surgeon's ability to visualize the cavity. Asshown in FIGS. 7 to 8, an inserter 46 can then be slidably guided by thedistractor 12. Specifically, the surgeon slidably mates the guidefeatures 18, 32, if any, on the distractor 12 and the inserter 46 to oneanother, and the inserter 46 is slid distally along the distractor 12into the intervertebral space 42. Once the inserter 46 is placed withinthe cavity 42, the implant 48 can then be maneuvered so as to achievethe desired orientation.

The distractor assembly disclosed herein can also optionally include ameasurement system (not shown). The measurement system can be anyindication that allows a surgeon to determine the depth of placement ofthe distractor, a trial implant or the implant. In an exemplaryembodiment, however, the measurement system is formed along the entirelength of the shafts of the distractor, filler bar, and/or inserter, oronly on a portion thereof. In addition, the distractor can included atleast one colored band so as to color code for the height of thedistraction paddle that the distractor can be matched to a similarlycolor coded trial implant and/or implant so that a surgeon can readilyensure that all are of the same height.

As noted above, the distractor assemblies disclosed herein can have avariety of features to assist in implanting the spinal prosthesis, suchas those features shown in FIGS. 9 to 43. Specifically, FIGS. 9 to 26illustrate distractors having features that assist a surgeon ininserting an implant into an intervertebral space at a desired angle. Atthe outset it should be noted that the distractor of the embodimentsdescribed below can have features and methods of use similar to those ofdistractor 12 discussed above.

FIGS. 9 to 11 illustrate one embodiment of a distractor 112 thatincludes a paddle 122 having an angled distal end 122 b, and thusproviding an angled guide surface 122 c. Many times, an implant isdesigned for placement at a certain angle of trajectory between theadjacent vertebrae and/or a surgeon chooses a particular angle ofplacement in order to achieve desired fusion characteristics. Minimallyinvasive approaches to the disk space provide well documentedadvantages, however, establishing a minimally invasive access portalwhile sparing sensitive nerve tissues from contact and possible damagerequires approach angles to the disk space that may not match thedesired angle of placement of the implant. For example, a typical TLIFapproach may take a 35° angle (plus or minus depending on the anatomy ofa particular patient) while the desired angle for placement of theimplant may be 45°. Providing an angled distal end 122 b on thedistractor paddle 122 allows the surgeon to carefully guide the implantduring insertion to the desired angle with a reduced chance ofcontacting sensitive nerve tissue. While the distal end 122 b of thepaddle 122 can have a variety of angles as desired by the surgeon, inthe illustrated embodiment, the distal end 122 b of the paddle 122 hasan angle of about 20°.

Paddle 122 can further include opposed overhanging tabs 123 a, 123 b anda curved distal end 122 b. The overhanging tabs 123 a, 123 b can be anyconfiguration that can serve as a guide for the implant 148, however, asshown, the overhanging tabs 123 a, 123 b are rectangular and extendhorizontally from the guide surface 122 c of the paddle 122.

In use, as an inserter (such as inserter 146) is slid distally along theshaft 114 of the distractor 112, the overhanging tabs 123 a, 123 b ofthe paddle 122 can slidingly engage the outer edge surfaces of theimplant 148. Once engaged, the implant 148 is guided along the length ofthe paddle 122. As the implant 148 approaches the distal end 122 b ofthe paddle 122, the angled distal end 122 b urges the implant 148 intothe desired orientation within the intervertebral space 142.

FIGS. 12 to 13 illustrate another embodiment of an angled distractor 212that includes a shape memory metal shim 211. While the metal shim 211can have any configuration to allow for the angled insertion of animplant 248, as shown the memory metal shim 211 is provided as aseparate element from the distractor 212 that is placed along the sideof the shaft 214 and paddle 222 of the distractor 212. Shim 211 can beheld flat to the shaft 214 and/or paddle 222 of the distractor by one ormore guide elements 213.

In use, extension of the shim 211 distally along the paddle 222(generally by pushing on a proximal end or feature of the shim) beyondthe guide elements 213 causes the shim to return to a curved shape. Theangle of curvature of the shape memory metal shim 211 can be any anglethat allows a surgeon to implant an spinal prosthesis into anintervertebral space 242, however in an exemplary embodiment, the curveof the shim 211 has an angle of about 20°. An implant 248 is theninserted into the intervertebral space 142 and, upon contact with theshim 211, is directed towards the desired placement angle within theintervertebral space 242. The shim 211 can also beretracted/straightened so that retraction of the distractor 212 does notdisplace the implant and so that retraction of the distractor does notdisturb sensitive tissue.

The shim 211 can be made of any biocompatible material known to haveshape memory or superelastic properties such as, for example, theNITINOL (an acronym for Nickel Titanium Naval Ordnance Laboratory)family of intermetallic materials, which contain a nearly equal mixtureof nickel (55 wt. %) and titanium. One skilled in the art willappreciate that the ability of the shim 211 conform to the shape of thedistractor 212 during insertion and then retain its curved shape once itis placed within the intervertebral space 242 allows for a reducedprofile for insertion and retraction through a minimally invasivesurgical access point.

FIGS. 14 to 17 illustrate an alternate embodiment of a distractor 312that includes a paddle 322 having a shape memory metal shim 311 similarto metal shim 211 (described above), as well as extension shoulders 333a, 333 b. While the extension shoulders 333 a, 333 b can have a varietyof configurations, in an exemplary embodiment, they are slidably locatedon the paddle 322 and extendable from the superior and inferior sidesthereof. However, in an alternate embodiment (not shown), a singleextension shoulder can be formed on the paddle.

In use, following insertion into an intervertebral space 342 androtation of the paddle 322 to a distracting position, the distalmovement of the shim 311, and in particular, contact between drivingshoulders 313 on the shim 311 and the extension shoulders 333 a, 333 b,drives the extension shoulders 333 a, 333 b upward and downward,respectively, to further distract the intervertebral space 342. Whileextension shoulders 333 a, 323 b can increase the height of the paddle322 by any amount as desired by the surgeon to achieve and maintain adesired level of distraction of intervertebral space 342, in anexemplary embodiment, the paddle has a height of approximately 7 mm andextension shoulders 333 a, 333 b increase the diameter of the paddle 322by an amount up to approximately 4 mm. By providing at least some of thedistraction height by extension rather than rotation, a more sureplacement of the distractor can be achieved with less movement withinthe cavity during distraction. Moreover, following extension of theextension shoulders 333 a, 333 b, the memory metal shim 311 extendsbeyond the distal end 322 b of the paddle 322, and retains its curvedshape, such that the surgeon can place the implant 348 into the cavity342 at a desired angle.

FIGS. 18 to 20 illustrate an alternate embodiment of a distractor 412having an internal shim 409, as well as extension shoulders 433 a, 433b. While the internal shim 409 can be formed in a variety of ways, asshown the internal shim is 409 is formed within a sheath 407 surroundingthe shaft 414 of the distractor 412. The internal shim 409 can alsoinclude an expansion mechanism such that, in use, and similar to thememory metal shim 211 discussed above, the internal shim 409 drives theextension shoulders 433 a, 433 b upward and downward, respectively, asthe surgeon desires.

Alternatively, as shown in FIGS. 21 to 23, the expanding shoulders 533a, 533 b of a distractor 512 can be driven by an internal shim 509having a linkage assembly 505. While the linkage assembly 505 can beformed in a variety of ways, as shown the linkage assembly 505 is alsoformed within a sheath 507 surrounding the shaft 514 of the distractor512. In use, similar to the embodiment above, the internal shim 509 candrive the linkage assembly 505 to control the height of the extensionshoulders 533 a, 533 b as desired.

FIGS. 24 to 26 illustrate another embodiment of a distractor 612 havingan inserter arm 660 for positioning the distractor. Distractor 612 caninclude an internal shim 609 and extension shoulders 633 a, 633 b,similar to those as discussed above. The inserter arm 660 can be removedafter placement of the distractor 612, and a cable 662 is left behindextending distally from the distractor 612.

In use, the shim 609 drives the extension shoulders 633 a, 633 b to seta height adjustment, similar to that as described above with respect toextension shoulders 333 a, 333 b. Once the cavity 642 is distracted tothe desired height, the inserter arm 660 can be slidably removed fromthe cable 662, resulting in the cable 662 extending out of theintervertebral space 642. The cable 662 can then either be removed orused as a guide for other surgical instruments. One skilled in the artwill further appreciate that the shim 609 can also optionally include asliding support 613 that can be slid along the shaft 614 of thedistractor 612 to lock the extension shoulders 633 a, 633 b in place,and help secure the distracted height of the cavity 642.

The cable 662 can be made from a variety of materials depending upon itsdesired use by the surgeon. For example, if the surgeon desires thecable to be used as a guide for future instruments or procedures, thecable can be made of any desirable surgical material of sufficient guidestrength.

FIGS. 27 to 36 illustrate implant inserters having features that assista surgeon in inserting an implant into an intervertebral space at adesired angle. At the outset it should be noted that the inserters ofthe embodiments described below can have features and can be used in amanner similar to that of inserter 46, discussed above. Moreover,depending upon the particular surgical assembly, the shafts of theinserters in the embodiments described below may or may not include aguide feature for slidably engaging with another surgical instrument.

FIGS. 27 to 29 illustrate one embodiment of an inserter 746 thatincludes a hinge pivot joint 770 and a linkage mechanism 772. While thehinge pivot joint 770 and the linkage mechanism 772 can have a varietyof configurations to drive the implant 748 to desired angulations, inone embodiment, the hinge pivot joint 770 and a linkage mechanism 772are formed at the distal end 746 b of the inserter 746, and locatedexternal to the shaft 752 thereof. Alternatively, the hinge pivot joint770 and the linkage mechanism 772 can be formed within a pathway (notshown) contained within the shaft 752 of the inserter 746. The inserter746 can also include a variety of means by which the surgeon can controlthe hinge pivot joint 770 and the linkage assembly 772, such as, forexample, a spring bias built into or placed on the pivot joint, andcontrol the movement in response to the bias by proximal or distalmovement of the linkage assembly. Thus, in use, the surgeon can maneuverthe linkage mechanism such that the hinge pivot joint 770 and a linkagemechanism 772 cooperate to place the implant 748 at a desired angle.

FIGS. 30 to 33 show another embodiment of an inserter 846 that includesmating impaction antis 878 a, 878 b to rotate the implant 848 to thedesired orientation. While the mating impaction arms 878 a, 878 b canrotate the implant 848 in a variety of ways, as shown, the matingimpaction arms 878 a, 878 b include a mating face 879 that allows highimpaction forces on the implant 848 by maintaining a high surface areaof contact. Handle or knob 883 is rotated to drive the impaction armsrelative to each other so as to rotate the implant, and the position ofthe knob can indicate the angle to which the implant is rotated as canbe seen in the differential angulations illustrated by comparing FIGS.30 and 31.

The mating face 879 can have any configuration, but preferably allowsfor a high surface area contact with the implant 848, however in anexemplary embodiment the mating face 879 includes an adjustable drivingmechanism having a movable protrusion 881 mated to the cavity of animplant 848. FIG. 32 illustrates an up close view of the translatingimpaction arms described above for an inserter that allows for implantrotation during insertion. The implant 848 includes an internal cavity885 in which a inserter driver 881 mates while allowing the implant torotate. The implant 848 is loaded by inserting the driver 881 into theimplant cavity 885 and rotating the driver 90 degrees as illustrated inFIG. 34 (loading position) and FIG. 33 (insertion position). The implant848 can be removed from the inserter by rotating the implant 90 degrees,in the reverse of the loading step for example.

FIGS. 34 to 35 illustrates another embodiment of an inserter 946 thatallows cable rotation of implant 948 with respect to vertebra 941 by acable 962 that is linked to the implant 948. Inserter shaft 952 permitsrotation of the implant in a hinge-like manner when the cable 962 isoperated by the surgeon to drive the rotation. When the inserter shaft952 is removed, the cable 962 must be disengaged from at least one ofthe implant 948 (in which case the cable 962 is removed with the shaft952) or the shaft 952 (in which case the cable 962 is left behind withthe implant 948). If the cable 962 is left behind, it can be formed, forexample, from a bioabsorbable material.

FIG. 36 illustrates an exemplary embodiment of an implant driver 1346that can be used with inserter 946 to permit rotation of the implant1348. The implant 1348 includes an external boss feature 1387 that isheld between two inserter tabs 1388 a, 1388 b. The inserter tabs 1388 a,1388 b can have a variety of configurations, however in an exemplaryembodiment, they include an inserter tab movement mechanism that allowsa surgeon to adjust the angulation of the implant 1348, for example byusing cable 962 from the embodiment of FIGS. 34 and 35. In one sense,external boss feature 1387 and tabs 1388 a, 1388 b are the inverse ofcavity 885 and inserter driver 881 from the embodiment of FIGS. 32 and33. Both configurations can allow angulation of the implant, but bycontact with external and internal surfaces of the implant respectively.

In other embodiments of the present invention, such as those shown inFIGS. 37-43, the inserter can have a controlled insertion feature toallow incremental insertion and placement of an implant 1048, such as,for example a ratchet gun. Such a gun may have a variety ofconfigurations known in the art, as shown in FIG. 37, the ratchet guninserter 1080 can include a flexible sheath 1081 to protect the neuraltissue from injury during insertion into the intervertebral space 1042of implant 1048 through minimally invasive access port 1082. Ratchet guninserter 1080 can further include a flexible inserter connection 1085,such as metal laser cut tubing or helical springs, can be used to allowfor implant rotation as described in other embodiments.

FIGS. 38 and 39 show one embodiment of a ratchet gun 1180 that includesdistraction paddles 1184 a, 1184 b. While the distraction paddles 1184a, 1184 b can have a variety of configurations known in the art, in anexemplary embodiment, they extend from the distal most end of theratchet gun and are shaped and sized such that they fit against theinner surfaces of the superior and inferior vertebrae 1141, 1143. Asthis embodiment includes paddle distractors, inserter 1180 is notintended to be guided by a paddle distractor as with embodimentsdescribed above.

In use, the surgeon inserts the ratchet gun inserter 1180 into theintervertebral space 1142 and squeezes the handle of the gun (likelyrepeatedly) so that implant 1148 slides between distraction paddles 1184a, 1184 b and extends the paddles away from each other to distract theintervertebral space 1142.

As further shown in FIGS. 40 and 41, a ratchet gun inserter 1280,similar to ratchet gun inserter 1180, can include a rotating inserter1247 that can have any configuration as described herein (above in FIGS.27 to 36). Alternatively, as shown in FIGS. 42 and 43, the ratchet gun1280 can include a memory metal shim 1211, such as that described inFIGS. 12 and 13 above to allow insertion of an implant at a desiredangulation.

A variety of implants can be used with the instruments disclosed above,such as, for example, the implants disclosed in U.S. Pat. No. 4,743,256to Brantigan, U.S. Pat. No. 4,834,757 to Brantigan, U.S. Pat. No.4,878,915 to Brantigan, U.S. Pat. No. 5,192,327 to Brantigan, U.S. Pat.No. 5,425,772 to Brantigan, U.S. Pat. No. 5,716,415 to Steffee, U.S.Pat. No. 5,984,922 to Mckay, U.S. Pat. No. 6,245,108 to Biscup, as wellas the implants disclosed in FIGS. 44 to 46. While the implants can havea variety of configurations, in an exemplary embodiment, as shown inFIG. 44, the implant 1448 has opposed front and back ends 1448 a, 1448 band parallel side surfaces 1448 c, 1448 d. Upper and lower surfaces 1448e, 1448 f that engage the adjacent vertebrae extend between the sidesurfaces 1448 c, 1448 d, and such a cavity 1493 is formed within thecenter of the implant 1448.

The back end 1448 b of the implant 1448 can have a profile and featuresto mate with an inserter instrument such as are known in the art or asdescribed above. Additionally, at least one slot 1490 forvascularization can be formed in at least one of the parallel sidesurfaces 1448 c, 1448 d and/or the upper and lower surfaces 1448 e, 1448f. While the slots 1490 can have a variety of shapes, e.g., circular,ovular, spherical, as shown the slot is ovular. Additionally, at leastone of the parallel side surfaces 1448 c, 1448 d and/or the upper andlower surfaces 1448 e, 1448 f has a plurality of pyramid-shaped teeth1492 formed thereon and extending outward to contact the superior andinferior vertebral surfaces 41, 43 and to resist retropulsion of theimplant during or after insertion.

Further, as shown in FIG. 44, the front end 1448 a of the implant 1448can have a geometry that allows for entry into the disk past neuralelements and for easier manipulation in the disk space. While thisgeometry can have a variety of forms, in an exemplary embodiment, it isa bullet-shaped profile, with a bulleted front profile in at least one,but preferably two planes. One skilled in the art will appreciate thatthe implant having a bullet formed in two planes is able to moreeffectively distract the vertebrae and neural tissue.

Further, the interior of the parallel side surfaces 1448 c, 1448 dand/or the upper and lower surfaces 1448 e, 1448 f can include aplurality of ridges 1491 formed thereon for the maximum retention of thebone graft material within the cavity 1493. While the ridges 1491 canhave a variety of shapes, in an exemplary embodiment the ridges 1491 canbe slots that extend vertically along the interior surface of theparallel side surfaces 1448 c, 1448 d and/or the upper and lowersurfaces 1448 e, 1448 f. Alternatively, the ridges 1491 can be slotsthat horizontally extend along the inner surface of the parallel sidesurfaces 1448 c, 1448 d and/or the upper and lower surfaces 1448 e, 1448f. Moreover, in an additional embodiment, the inner surfaces of theparallel side surfaces 1448 c, 1448 d and/or the upper and lowersurfaces 1448 e, 1448 f can include both vertically and horizontallyextending ridges 1491.

In addition, as shown in FIGS. 45 to 46, upper surface 1448 e of theimplant 1448 can have a dome structure formed thereon. While the domecan have a variety of configurations, in an exemplary embodiment thedome is angled such that it corresponds to the shape of the superior andinferior vertebrae at a desired angle of rotation. One skilled in theart will appreciate that this implant allows for insertion at an anglethat is approximately 35° off of the midline of the vertebrae.

The materials used for forming the implants disclosed herein can vary.One preferred material from which the implant can be made is a carbonfiber reinforced polymer. Other materials from which the implants can bemade include metals, metal alloys, biologically compatible polymers,allograft bone, and combinations of these materials. Examples ofsuitable polymers include polyether sulfone, polycarbonate, andbioabsorbable polymers, and examples of suitable composites includecarbon fiber reinforced polymers. Examples of suitable metals includetitanium, stainless steel, tantalum, cobalt chromium, aluminum, andcombinations thereof.

As noted above a graft material funnel 2 can also be used with thedistractor assembly disclosed herein. As shown in FIG. 47, the graftmaterial funnel 2 has proximal and distal ends 2 a, 2 b connected by ashaft 6. The proximal end 2 a can have a variety of features known inthe art to contain bone graft material to be siphoned into the implant.While the shaft 6 can have a variety of configurations, such as elongateor curved, as shown it is curved. One skilled in the art will appreciatethat the curved shape of the shaft allows rotation to implant graftmaterial to a desired location. Additionally, while the shaft 6 can bemade from a variety of materials, in an exemplary embodiment, the shaft6 is made from a material that allows for the shaft diameter to havesome flexibility, such that the graft material can be introduced intothe funnel 2 without clogging.

The instruments described herein can be made from any suitable surgicalgrade material, including surgical grade stainless steel, titanium,aluminum, tantalum, cobalt chromium, plastics, and combinations andcopolymers thereof.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, except as indicated by the appended claims. Allpublications and references cited herein are expressly incorporatedherein by reference in their entirety.

What is claimed is:
 1. A surgical instrument system, comprising: anarticulating implant inserter including a shaft; and an articulatableimplant holding element having a hinge pivot joint and located on adistal end of the shaft, the articulatable implant holding element beingoperable from a proximal portion of the shaft to releasably hold animplant; and an implant having a connecting element that cooperates withthe articulatable implant holding element to allow articulation of theimplant to a desired angle upon operation of the implant holdingelement.
 2. The system of claim 1, wherein the implant connectingelement is internal to the implant.
 3. The system of claim 1, whereinthe implant connecting element is external to the implant.
 4. The systemof claim 1, wherein the articulatable implant holding element includestwo sliding elements having distal implant impaction faces, the implantholding element being operable from a proximal handle to providerelative sliding in a proximal-distal direction along the shaft toselectively articulate the implant to a desired angle.
 5. The system ofclaim 4, wherein the position of the handle acts as a visual indicatorfor an angle through which the implant has been rotated.
 6. The systemof claim 1, wherein the implant is a fusion cage.
 7. A surgicalinstrument system, comprising: an articulating implant inserterincluding a shaft; and an articulatable implant holding element locatedon a distal end of the shaft, the articulatable implant holding elementbeing operable from a proximal portion of the shaft to releasably holdan implant; and an implant having a connecting element that cooperateswith the articulatable implant holding element to allow articulation ofthe implant to a desired angle upon operation of the implant holdingelement; wherein the articulatable implant holding element includes twosliding elements having distal implant impaction faces, the implantholding element being operable from a proximal handle to providerelative sliding in a proximal-distal direction along the shaft toselectively articulate the implant to a desired angle; and wherein theposition of the handle acts as a visual indicator for an angle throughwhich the implant has been rotated.
 8. The system of claim 1, whereinthe implant connecting element is internal to the implant.
 9. The systemof claim 7, wherein the implant is a fusion cage.